Products in the form of cough drops have long been known as vehicles for the delivery of medicaments aimed at soothing sore or irritated throats. Such medicaments include analgesics, antitussives, expectorants, cooling agents such as menthol, and warming agents such as ethanol or gingerol. The medicament can be administered by way of a throat drop or lozenge which releases the active agent upon sucking. Particularly in the case of a volatile active agent, the product can also provide relief from cold symptoms by way of clearing the nasal passages.
EP-A-431,376, for example, describes hard confections for sustained release treatment of sore throats comprising hydrogenated isomaltulose and an active ingredient which can be an antitussive or antihistamine but can also be a volatile oil such as menthol or eucalyptus. The confection normally contains a further flavouring agent such as lemon, honey or cherry but which can also be menthol or eucalyptus.
A well accepted form of throat drop is a centre-filled throat drop consisting of an edible shell and a liquid centre-filling. The liquid centre provides a pleasant soothing effect on the throat which may be further enhanced by an active agent as described above.
One of the problems with such throat drops is to provide the optimum degree of liquidity in the centre filling. Typically the edible shell cannot tolerate a high degree of moisture in the filling for reasons of product stability. Levels of moisture in the filling are usually less than 20%. The bulk of the filling usually comprises a bulk sweetener to improve the palatability of the product. These constraints often mean that the viscosity of the filling is rather high, say in excess of 50,000 mPa.s, resulting in a reduction in perception of liquidity of the centre.
U.S. Pat. No. 3,894,154 discloses the inclusion of a glycerine in the centre of liquid centre-filled chewing gum for retarding increases in viscosity of the liquid fill portion. Whilst such an approach is effective, especially within a corn syrup base, it is often not of itself sufficient.
U.S. Pat. No. 4,157,402 discloses the use of an emulsifier in the filling of a centre-filled chewing gum to prevent the flavoured liquid filling penetrating into the surrounding gum composition, thus improving the flavour retaining capacity of the chewing gum.
It has now surprisingly been found that the addition of sufficient emulsifier to the liquid filling of a centre-filled hard candy to reduce its contact angle against a gelatine coated plate from more than 120.degree. to a value in the range of 90 to 120.degree., is sufficient to provide an improvement in the perception of liquidity, and thus throat soothing, even though such addition may result in an increase in viscosity.
It is accordingly an object of this invention to provide centre-filled candy compositions, especially throat drops, with an improved perception of liquidity of the filling.
It is a further object of the invention to provide centre-filled throat drops, with an improved perception of throat soothing.